In general, zero forcing beamforming (ZFBF) is a linear precoding scheme that decouples a multiuser channel into multiple independent sub-channels and reduces a precoder design into a power allocation problem. Typically, ZFBF performs well in high signal-to-noise ratio (SNR) environments. Furthermore, it is possible to incorporate additional techniques into ZFBF, such as dirty paper coding (DPC), to help improve performance.
Closed loop multi-user multiple input and multiple output (MU-MIMO) technologies recently have attracted significant attention from both standardization bodies and telecommunication industries around the world. By jointly taking advantage of multiuser diversity and inherent space-time diversity of MIMO system, MU-MIMO can significantly improve system throughput and achieve higher bandwidth efficiency compared to conventional single user MIMO.
ZFBF is a promising candidate of close loop MU-MIMO technologies for next generation wireless communication systems. However, inherent quantization error accumulation and poor signal and interference to noise ratio (SINR) estimation may prevent ZFBF from commercialization.